Got an apex pipe and installed it on our eton..It absolutely killed the power all around at first..I played with the rollers and now it pulls like a freight train but I just can't get it to come out of the hole..It goes about 2-3 bike lengths very sluggishly and then takes off like crazy..I had three 8 gram rollers mixed with three 5 gram rollers originally and then went to all 5 gram rollers which was much better but still not much better on the bottom end..I didn't have any lighter rollers so I took out one roller..It didn't seem to help much but it still gained mph on the top end..The motor obviously likes to rev with the apex pipe...I changed the springs in the rear clutch to the red coloured ones but still no improvement off the line...The motor is stock with the exception of a uni filter and some boyeseen reeds....I would appreciate any advice to get this thing to pull off the line like it does after it goes 10 or 15 feet!

 

Not that I am an expert but when we opened up our stock exhaust we had to turn out the air to fuel mixture screw to lean it up a bit on the idle end of the spectrum. What engagment are the three red springs, I know we went with purple and got pretty good results.
Let us know what you end up doing, that is good info to get out there.

 

I bought the spring kit a couple of years ago from Hetricks....I "think" it goes yellow blue and red in order of getting stiffer..The plug does look a little lean but the bike runs awesome other than the low end bog..As soon as it hits a certain rpm its like flicking a light switch and it takes off like a rocket..I just can't seem to get the rpms up enough from a dead stop to eliminate the bog..

 

Here is a short clip of the bike taking off till it hits its power band just at the edge of my garage..

 

How much have you messed with the pilot jet and what size are you running? Like I said I am no expert but here is what I did. I went up from a 40 pilot to a 55,dropped the needle one notch, and went to a 148 main jet and i have the air fuel screw out one turn. This is on a keihen 32mm so if your running a mikuni you'll have to adjust. It really woke it up on the bottom end and gave me more on top which was a pleasent suprise.
Let me know what happens.

 

Ok after waiting 20 minutes for the video to load on my dial up I dont think I would change the carb, it sounds like 1000-1250 engagment. I think you need to come in higher with the pipe. It doesn't sound like it is coming in any higher than my stock limited. I think if you came in at 1500-1750 you wou have an awesome viper, but I wouldn't run much heavier than 5.5-6 gram weights. You wouldn't have access to a Vapor computer to use, they are great for rpm testing. Put a set of 1750's engagment springs, 5 g weights and a white main spring and see what happens.

 

Oldyeller, did you try what I mentioned in my PM?

 

Thanks for the replies guys..The rear clutch torsion spring is still stock so that could be the problem..I will change it out for the red one I got from hetricks long ago......Jack I will install the 5 gram rollers so that will bring me to 30 grams total....I also have the 3 little red springs installed in the rear clutch....The carb is stock except for the #115 main jet I installed after going to the UNI filter..The pilot jet is the stock #43..Hetricks recommended I leave the pilot alone until I had the clutching dialed in..I hope the pilot is ok because I don't have a larger one..

 

I installed the red torsion spring today and installed all six 5 gram rollers back in the variator..It doesn't seem any better although I didn't have my son home to test it..Nailing the throttle on wet grass with nobody on it, it will not spin the tires...

 

It just seems that you need a higher engagment, in the video it just sounds too low for a pipe that relies on rpms. The main red spring is the shifting spring so that won't effect the engagment, I would get a set of stiffer of the three little ones and have it come in harder.